The conventional electromagnetic electronic whiteboard has the structure of using an electromagnetic pen and a writing board. This type of digital board includes an internal antenna board of a matrix form, which is a substrate made of FR1 or FR4 fiber glass, PET, PVC, PS, or plastic thin film, covered with antenna loops in a two dimensional matrix (X axis and Y axis). The size of the drawing area of the digital board is determined by the two-dimensional antenna matrix. FIG. 1 shows a conventional two-dimensional antenna matrix. When the antenna loops are laid out on the printed circuit board (PCB), the X-axis antennas (x0-x12) and Y-axis antennas (y0-y9) will be laid out on different surfaces of the PCB, and via holes are used for crossing.
In a conventional electromagnetic whiteboard or a conventional electromagnetic writing tablet, a planar dual-board structure is used for the antenna loops. In other words, the antenna board is a rigid structure that is not bendable. Therefore, the drawing area on the board is also fixed and not adjustable. As a large electronic whiteboard may be used in a smaller working environment, the storage and transportation of the electronic whiteboard are both inconvenient and expensive.